1. Field of the Invention
The present invention relates to a digital signal reproduction apparatus and a digital signal reproduction method which can preferably be used for an audio apparatus, a video apparatus, and the like, and particularly relates to a signal reproduction apparatus, a digital signal reproduction method, a digital signal recording apparatus, a digital signal recording method, and a recording medium which are capable of providing a pleasant, comfortable sound and image.
2. Description of the Prior Art
The natural phenomena surrounding us such as wind, light, and temperature have temporal and spatial fluctuations. These fluctuations are considered to be a factor of pleasantness which cannot be obtained from artificial devices. Recently, special attention is paid on 1/f fluctuation as a desirable fluctuation for humans as biological beings.
As for an electronic apparatus employing the 1/f fluctuation, Japanese Patent Laid Open Hei 2-160297 discloses a technique for adding to a reproduced sound from a compact disk (CD) a signal of a white noise equalized according to the 1/f fluctuation via a high pass filter (HPF). Moreover, Japanese Patent Laid-Open Hei 4-275596 discloses that the 1/f fluctuation having a parameter section for adding a vibrato effect can add a chorus effect, i.e., sound and frequency fluctuate in a pleasant way. Furthermore, Japanese Patent Laid-Open Hei 4-280197 discloses a technique for adding reverberation having a spatial fluctuation.
Moreover, Japanese Patent Laid-Open Hei 7-28177 discloses that according to a voltage fluctuation obtained from a current fluctuation, it is possible to control the temperature and the wind amount, or the wind. Japanese Patent Laid-Open Hei 7-262403 discloses a technique for synthesizing a natural animation having the 1/f fluctuation characteristic. Japanese Patent Laid-Open Hei 8-6562 discloses a technique for converting a CD reproduction signal into an acoustic signal.
On the other hand, with the advent of the CD, DVCR (digital video cassette recorder), DVD (digital video disk) and the like, an audio signal and a video signal are rapidly digitized. The digitization has a meaning in eliminating the aforementioned fluctuations (noise) but this leads to a criticism of audio manias that the sound is too plain and flat. Actually, it is known that the acoustic power fluctuation and the frequency fluctuation of the classic music also have the 1/f fluctuation.
Digitization is carried out through sampling and quantization by a sample hold circuit and an A/D converter, respectively, with a constant width and size. There is also a technique of ADPCM (adaptive differential pulse code modulation) which changes the quantization width, but the width determined has no fluctuation.
Moreover, when a digital signal CD and an analog signal LP record are prepared from one and the same master tape, there is a evaluation that the CD is inferior because it cannot provide a depth feeling. On the other hand, there is a high evaluation for a music of the 1/f fluctuation.
It is therefore an object of the present invention to provide a digital signal reproduction apparatus, digital signal reproduction method, a digital signal recording g apparatus, a digital signal recording method, and a recording medium in which fluctuation is added to a sampling or quantization process so as to increase pleasantness, eliminating the digital flatness.
In order to achieve the aforementioned object, the digital signal reproduction apparatus according to the present invention includes: fluctuation generating means for generating the 1/f fluctuation; a reproduction system for reproducing a digital signal; and digital/analog conversion means for converting the digital signal into an analog signal; the digital/analog conversion means controlling the digital/analog conversion characteristic according to the 1/f fluctuation generated by the fluctuation generating means.
The aforementioned digital signal reproduction apparatus is enables to obtain a pleasant sound and image having a profound depth feeling like in the natural world by adding the 1/f fluctuation characteristic in the temporal direction and the amplitude direction of an audio data and a video data which have been digitized.
The digital signal reproduction method according to the present invention generates a 1/f fluctuation; reproduces a digital signal; and controls digital/analog conversion characteristic according to the 1/f fluctuation when converting the reproduced digital signal into an analog signal.
The aforementioned digital signal reproduction method enables to obtain a pleasant sound and image having a profound depth feeling like in the natural world by adding the 1/f fluctuation characteristic in the temporal direction and the amplitude direction of an audio data and a video data which have been digitized.
The digital signal recording apparatus according to the present invention includes: fluctuation generating means for generating a 1/f fluctuation; analog/digital conversion means for converting an analog signal into a digital signal while controlling the analog/digital conversion characteristic according to the generated 1/f fluctuation; and a recording system for recording the digital signal on a recording medium.
The aforementioned digital signal recording apparatus enables to record on a recording medium a digital signal having a pleasant sound and image fluctuations like in the natural world by converting an analog signal into a digital signal while controlling the analog/digital conversion characteristic according to the 1f fluctuation.
The digital signal recording method according to the present invention generates a 1/f fluctuation; converts an analog signal into a digital signal while controlling analog/digital conversion characteristic according to the 1/f fluctuation generated; and records the digital signal on a recording medium.
The aforementioned digital signal recording method enables to record on a recording medium a digital signal having pleasant sound and image fluctuations like in the natural world by converting an analog signal into a digital signal while controlling the analog/digital conversion characteristic according to the 1/f fluctuation.
The recording medium according to the present invention contains a program data for generating a 1/f fluctuation, reproducing a digital signal, and converting the reproduced digital signal into an analog signal while controlling the digital/analog conversion characteristic according to the 1/f fluctuation.
The recording medium according to another aspect of the present invention contains a program data for generating a 1/f fluctuation and converting an analog signal into a digital signal while controlling the analog/digital conversion characteristic according to the generated 1/f fluctuation, so as to record the converted digital signal on a recording medium.